共查询到19条相似文献,搜索用时 312 毫秒
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评述了温敏水凝胶、pH敏感水凝胶的环境敏感特性并探讨了环境敏感的机理.按其在环境中的不同表现,温敏凝胶可分为热胀型和热缩型,pH敏感水凝胶可分为阴离子型、阳离子型和两性型.介绍了光敏感水凝胶、电敏感水凝胶、磁响应水凝胶微球的环境敏感原因和应用研究现状.指出含有多种环境敏感特性的复合凝胶在近年来得到越来越多的关注,在凝胶材料性能的改善上还有大量工作要做. 相似文献
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敏感型材料是指能感应外部条件并做出响应的材料,具备感知、驱动、控制功能,是当今研究热点。其中环境敏感型材料敏感度高、响应性显著、自调节能力突出,因此在油气钻采中有着广泛应用。环境敏感型材料可有效改善钻井液流变性、增强堵漏能力、提高采收率以及酸化增黏效果明显。本文综述了pH敏感材料、CO2敏感材料、磁敏感材料、温敏材料、盐敏材料及压敏材料研究现状,并对上述材料从应用场合、合成方法、性能特性等方面进行分析,对环境敏感型材料今后在油气钻采中的应用作出展望,同时指出部分环境敏感型材料存在响应范围小、不易降解、稳定性差、储层保护能力偏弱的问题,建议未来环境敏感型材料应开发更好的纳米粒子、高分子聚合物、功能单体来推动其在油气钻采中的进一步发展。 相似文献
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从响应机理、合成方法、研究方法和发展趋势几个方面介绍电场敏感凝胶。综述了电场敏感的凝胶的渗透压理论、场理论等响应机理。其合成方法有单体交联聚合I、PN法合成等凝胶制备方法,关于凝胶的研究方法包括红外光谱、扫描电镜、在直流电场下的响应特性。同时,介绍了凝胶在药物释放、组织培养、化学机械等体系的应用。最后,展望现阶段电场敏感凝胶理论的不足和研究发展趋势。 相似文献
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对应用于油井井下油水两相流含水率测量的电导传感器敏感场分布特性进行了研究。建立了传感器管道轴线位置含一柱状油泡时敏感场分布的理论模型,利用Schwartz交替迭代法求解了敏感场内的电势分布和电流密度分布,分析了不同油泡大小和所处位置对传感器输出结果的影响。为进一步深入研究电导传感器的响应特性奠定了基础。 相似文献
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结构型重垢液体洗涤剂 总被引:2,自引:0,他引:2
叙述了结构型重垢液体洗涤剂中球形层状液晶的特性 ,影响球形层状液晶形成的因素及其体积分数对结构型重垢液体洗涤剂稳定性的影响。介绍了电解质、聚合物和抗絮凝聚合物对结构型重垢液体洗涤剂粘度、稳定性的影响及其作用机理。 相似文献
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Yi Liu Han Zhang Harshit Porwal James JC Busfield Ton Peijs Emiliano Bilotti 《Polymer International》2019,68(3):299-305
Conductive polymer composites (CPCs) with pyroresistive behaviour are of interest for a wide variety of applications such as safe batteries, resettable fuses, temperature sensors and self‐regulating heating devices. Due to their ease of processing, low density, tunable electrical properties, good oxidation resistance, and good flexibility and toughness, CPCs have become the preferred choice of pyroresistive materials in a number of applications. The pyroresistive behaviour of CPCs can be tuned to satisfy the specific requirements of different applications. In this perspective paper, recent progress in the use of pyroresistive CPCs is reviewed. In particular, various factors influencing their performance are discussed and compared, in connection with the associated application, with a special focus on reproducibility and positive temperature coefficient intensity levels. Some of the remaining challenges are identified, together with future prospects in this evolving field. © 2018 Society of Chemical Industry 相似文献
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绿色高效溶剂——离子液体 总被引:3,自引:0,他引:3
室温离子液体是由有机阳离子和无机或有机阴离子构成的、在室温或室温附近温度下呈液体状态的盐类.本文综述了离子液体的4种合成方法,重点介绍了离子液体的物化性能及影响物化性能的因素,同时还对离子液体作为绿色高效溶剂在化学反应、电化学及分离工程中的应用进行了简要介绍. 相似文献
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Polymer/carbon nanotube composites for liquid sensing: Model for electrical response characteristics
Electrically conductive polymer composites (CPCs) based on carbon nanotubes (CNTs) and polycarbonate were investigated regarding their electrical resistance change in different solvents like tetrahydrofuran, acetone, and ethyl acetate. CPCs containing 0.086 to 2.778 vol.% CNT were melt mixed using a twin-screw extruder under optimised conditions and subsequently compression-moulded.All sensing experiments revealed a resistance increase of CPCs having a U-shaped sample geometry during solvent immersion. Light microscopy investigations have shown that the diffusion of solvents into CPCs can be monitored in terms of a pronounced diffusion front, separating a swollen skin from the dry core. Based on this observed skin-core morphology, a model allowing the calculation of the time depending relative resistance change has been proposed considering several factors like diffusion parameters, composite characteristics, and geometrical values.Simulated response curves based on the model were compared with experimental data obtained on the CPCs and very good agreement was observed. Using this model the influence of CNT content and kind of solvent could be described exactly. 相似文献
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Since the emergence of large aspect ratio and multifunctional conductive fillers, such as carbon nanotubes, graphene nanoplates, etc., conductive polymer composites (CPCs) have attracted increasing attention. Although the morphological control of conductive networks in CPCs has been extensively investigated as an important issue for the preparation of high performance CPCs, recent extensive progress has not been systematically addressed in any review. It has been observed that the morphological control of conductive networks during the preparation of CPCs has crucial influence on the electrical properties of these composites. Several methods have been shown to be able to control the network structure, and thus, tune the electrical properties of CPCs, including the use of shear, polymer blends, thermal annealing, mixed filler, latex particle etc. Moreover, many novel and exciting applications have been extensively investigated for CPCs, such as stretchable conductor, electroactive sensors, shape memory materials and thermoelectric materials, etc. Therefore, the morphological control of conductive network in CPCs is reviewed here. Issues regarding morphology characterization methods, morphological control methods, resulted network morphology and electrical properties are discussed. Furthermore, the use of CPCs as electroactive multifunctional materials is also reviewed. 相似文献
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节水减排是工业发展的必然趋势和重要组成部分。本文从生产实际出发,在对循环冷却水系统及水源进行介绍的基础上,对气体液滴夹带现象及其机理、影响因素进行了分析,并对新型气液夹带控制技术进行了综述。 相似文献
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2,1,3-苯并噻二唑(BTD)类化合物具有优异的光电性能,被广泛应用于有机光电领域。合成具有液晶性的苯并噻二唑类衍生物可以达到改善这类化合物的光电性能的目的。综述了近年来苯并噻二唑类液晶化合物的研究进展,包括含单个苯并噻二唑单元的非对称和对称液晶及含两个苯并噻二唑单元的液晶。介绍了该类化合物的分子结构、液晶自组装行为以及光电性能之间的关系。最后,对苯并噻二唑类液晶化合物研究现状进行了总结,指出当前研究所存在的局限性,并对未来该类液晶化合物的分子设计和发展前景进行了展望。 相似文献
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近年来,在分子中引入氟原子进行改性成为材料研究的热点之一。分子中引入氟原子后,可以影响其热性能、电荷输运性能以及液晶的相行为等,最终改善材料的热、光、电和磁等性质。含氟盘状液晶由于具有较高的载流子迁移率,其合成方法和性质得到了广泛的关注。在含氟盘状液晶分子的平面核上、外围侧链或桥体上取代的氟原子均能显著改变液晶的相变性质,如提升液晶相的热稳定性和柱状相的有序度等。该文综述了近十年来具有代表性的利用氟原子改性盘状液晶的研究进展,进一步证实了氟化有利于改善液晶性质,并进一步归纳了含氟盘状分子在其他领域的应用。盘状液晶氟化后所表现出的优异性能,有助于启发科研工作者在药物合成、无机材料等领域引入含氟材料。 相似文献